Sash Beading

[wobs]

One possible design flaw in a traditional sash window is the outer sash bead. Most come right down to the sill. Surely it would be better if it left a gap or was cut at 45deg to allow water to drain off?

 

[malcolm]

My carpenter has cut the bottom of the bead away. I'll pop a photo up this evening.

 

[JanJonWestWales]

Our bespoke built sash windows dont have an "outer beading".
The bottom sash sits on the sill, with a draught strip. The sill is angled to allow water to flow away.
There is a "Parting beading" between the sashes and an "Inner beading" which can be removed to allow the sashes to be taken out for painting etc

 

[wobs]

Our bespoke built sash windows dont have an "outer beading".
The bottom sash sits on the sill, with a draught strip. The sill is angled to allow water to flow away.
There is a "Parting beading" between the sashes and an "Inner beading" which can be removed to allow the sashes to be taken out for painting etc

What is holding your top sash in place, to stop it from falling out? I am referring to the vertical beading on the outside edge of the frame keeping the top sash in place.

 

[JanJonWestWales]

Our bespoke built sash windows dont have an "outer beading".
The bottom sash sits on the sill, with a draught strip. The sill is angled to allow water to flow away.
There is a "Parting beading" between the sashes and an "Inner beading" which can be removed to allow the sashes to be taken out for painting etc

What is holding your top sash in place, to stop it from falling out? I am referring to the vertical beading on the outside edge of the frame keeping the top sash in place.

ah ok....the frame itself holds the top sash. There isnt an additional beading.
I think your refering to where this abuts the sill, and the gap between this and the inner sash at the base.
In which case I can see that this little tucked in corner can collect water.
Hadn't thought of cutting a gap at the sill.

 

[plasticpigeon]

I don't think it matters, many of my windows have rotted at the front of the sill, on the nose of you like, but none where you mention. Mine are Edwardian and set a half brick back from the face of the brickwork. If set flush with the face then perhaps it woud be more of a problem, but that is an earlier style I am less familiar with. A nicer solution to me would be to build up or stick on a fillet of something (putty, wood) to make sur that no water sits behind the outer lining where it meets the sill, but it has obviously not been an issue affecting the windows in my house.

 

[Feltwell]

Just to be contrary, it has been a problem here! That area has been bad on a couple of my windows and is definitely a water trap.

Whenever I renovate one now I take a small slice out with a multitool, if it's not already rotted away The change is barely noticeable.

The bay I'm working on at the moment, there was pretty much nothing solid left of the bottom 9" of the front part of the sash box, which forms the "bead" you speak of. Now replaced with some hardwood, hopefully this will last - it had been replaced before in the past by someone with some cheap softwood, not fitted very well.

 

[malcolm]

Here is a photo of mine. My carpenter is very fussy about drainage. The windows are full of slopes and vented cavities and I don't think he could stand the idea of water puddling at the bottom of the outer channel. I asked if it was an original feature or one of his and he just grinned.

 

[Feltwell]

Here is a photo of mine. My carpenter is very fussy about drainage. The windows are full of slopes and vented cavities and I don't think he could stand the idea of water puddling at the bottom of the outer channel.

Good for him! Here's what happens when water does gather, poor quality repairs are made and then water gathers and ingresses again - now part of my current repair project.





Note the use of expanding foam - rarely a good sign of a well executed repair :roll:

 

[88v8]

The junction of vertical boxing and cill is a weakness. The sashes I had made for our previous house did not suffer at that point but they were only 30 years old when we sold. Ours had extended cills - projected beyond the wall - which created another potential for water ingress.
Cutting an exit as Malcolm has done is good, except that it exposes end-grain.

The advent of stainless nails and screws, and two-part resorcinol glue, will be a big help with your repair, but it will still be a fiddly job. Where the end-grain sits down on the cill, I would at least give it a full paint system, preferably preceded by a soaking in Ronseal resin.

If there is any chance that water will still get in, I found the Ronseal ant-rot tablets effective over many years, but needless to say the H&S crackpots have deemed them daaaaangerous.
Understandable and prudent. After all, one could hardly open a paper with reading accounts of people suffering Disodium Octaborate poisoning after chewing their window cills, and nowadays one never hears of it.

I see the crackpots have also banned the clear wood preservative with which I have treated our bird table for the last 28 years. Lucky the birds don't know.

Ivor

 

[wobs]

Thanks guys, some good info here.

I have been treating all areas susceptible rot with the clear wood treatment prior to linseed oil.

 

[CliffordPope]

Here is a photo of mine. My carpenter is very fussy about drainage. The windows are full of slopes and vented cavities and I don't think he could stand the idea of water puddling at the bottom of the outer channel.

Doesn't the same argument apply to the fillet separating the two sashes? Rain could drive in between the fillet and the sash, run to the bottom, and then puddle behind the bottom of the fillet where it meets the sill?

 

[Feltwell]

It's much less likely, the bottom sash sits against the inside of it so any driven rainwater is more likely to run down at that joint and then harmlessly away down the cill - but yes, it's not impossible that water could get behind the parting bead. Again I leave a very small gap at the bottom to let any water escape, just in case.

In truth I doubt it would cause much of a problem - it's the bottom of the parting bead that would be most likely to be affected, they're easy to change (and often break when coming out anyway) and in my case at least I'm replacing all mine with ones with integral carriers for draught proofing as I renovate each window. None of my old ones, which are flush with the cill, have shown any signs of rot there.

I finished the main bay window sash today - so nice when they're done, it's a big heavy window that was really awkward to open before - now it's properly weighted, with new pulleys and (most importantly of all) the draught proofing in place on the beads which really reduces the friction, the sashes just glide smoothly up & down - as well as no draughts or rattles of course.

 

[Feltwell]

Well, here's a nearly finished part of the bay, just missing a piece to go on the front of the sash box - which can't go until the side window, round the corner, is ready - and of course finish decorating it when the weather warms up.



So today's was job was starting to tackle that side window. Right, sashes out, let's start cutting out the rotten bits at the bottom of the frame and see what's left eh?



So that will be not much then. :lol:

 

[wobs]

Wooaah.... that's about the same shade of green that I'm using.
Great minds and all that.

Nice work BTW. More than what I have time for. Probably struggle to work to that standard.

 

[MatthewC]

Our bespoke built sash windows dont have an "outer beading".
The bottom sash sits on the sill, with a draught strip. The sill is angled to allow water to flow away.
There is a "Parting beading" between the sashes and an "Inner beading" which can be removed to allow the sashes to be taken out for painting etc

The "Inner beading" is called the "Staff bead", isn't it?

I have two new sash windows which were specially made, and they had the front cut away so that there was no water trap on the cill; subsequently I have made the same modification on a new-ish window which needed it.

 

[Feltwell]

Wooaah.... that's about the same shade of green that I'm using.
Great minds and all that.

Nice work BTW. More than what I have time for. Probably struggle to work to that standard.

If I remember what else you've done and posted up here, I doubt that Wobs!

For this kind of job, an oscillating multi-tool really is an essential. I know people overhauled sash windows for many years before they were invented, but they really are a fantastic bit of kit for plunge cutting neatly in-situ as I have on that picture. A half-round blade to get the straight cuts started (easier to cut in a straight line with them - but you can't cut very deeply) and then a standard rectangular blade to plunge in to get the depth of cut all the way through the timber. SO much easier than hand saws and chisels. Fein are supposedly the best (but are eye-wateringly expensive), I've got a Makita cordless one and am very happy with it.

The shade of green - hmm, yes, jury's out on that one. The thought is to have creamy-yellow sashes (buttermilk?), as per the first picture, and green frames. I'm not sure at the moment if the green needs to be darker. I probably just need to be braver and go for it - I do tend to err on the safe side with colours.

All this rebuilding rotten windows and other "structural" jobs are easy, deciding what colour to decorate anything is a nightmare! :lol:

The "Inner beading" is called the "Staff bead", isn't it?

Yes it is - at least it is when I order them from Reddiseals - but I wouldn't be surprised if there are some regional variations.

 

[plasticpigeon]

I've also seen it called a "stop bead" in old books.